Effects of inoculants on the fermentation characteristics and in vitro digestibility of reed canary grass (Phalaris arundinacea L.) silage on the Qinghai‐Tibetan Plateau

To effectively use local available grass resources to cover the winter feed shortage on the Qinghai‐Tibetan Plateau, direct‐cut and wilted reed canary grass (RCG) silages were prepared by using a rolled‐bale system, and their ensiling characteristics and in vitro digestibility were studied. Silages were treated without (control) or with inoculants including LP (Lactobacillus plantarum), LPLB (L. plantarum, L. buchneri), and LPLBc (L. plantarum, L. buchneri, and cellulase), and were stored at ambient temperature (5.7–14.6°C) for 90 days. Compared with control, the inoculated silages increased (p < .05) lactic acid and acetic acid contents, and reduced (p < .05) final pH value and ammonia‐N ratio of total N. The highest WSC content (41.2 g/kg DM) occurred for LPLB‐inoculated silage, whereas LPLBc‐treated silage displayed the lowest contents of NDF (522.9 g/kg DM) and ADF (275.5 g/kg DM). In addition, LPLBc‐inoculated silage had the highest in vitro gas production (51.0 ml/g DM), in vitro DM digestibility (619.3 g/kg DM), and metabolic energy (9.6 kJ/kg DM). These results confirmed that treatments with inoculants at ensiling could improve silage fermentation and in vitro digestibility of RCG, and this could be a potential winter feed for animals on the Qinghai‐Tibetan Plateau.     

红壤丘陵区不同生态重建中红壤的微生物学性状

研究了中国科学院红壤生态试验站的优化农业生态模式的长期定位试验地里的常绿针叶林地(马尾松林)、落叶阔叶林地(小叶栎)、针阔混交林地(湿地松-小叶栎)、自然恢复地(受到人为干扰)、茶园地、柿子园地和花生地等样地，并且在附近选了疏草荒地作为对照。结果发现，不同生态重建模式与对照相比，在微生物学性状上均有很大程度的提高。总的趋势是农用果园地好于林地，林地好于自然恢复地。在剖面分布上，也有明显的层次差异，即随土层的增加而减少。     

饲喂方式对德州驴生长性能、营养物质消化率和盲肠微生物多样性的影响

本试验旨在研究饲喂方式对德州驴生长性能、营养物质消化率和盲肠微生物多样性的影响。选择体重[(215±10)kg]相近、2周岁左右的健康德州公驴15头,随机分为C1组(饲喂方式为先粗后精)、C2组(饲喂方式为先精后粗)、C3组[饲喂方式为全混合日粮(TMR)],每组5头,预试期7 d,正试期75 d。结果显示:1)C2组平均日增重极显著高于C1和C3组(P≤0.01),C1组干物质和酸性洗涤纤维消化率以C1组最高,C3组次之,C2组最低,C1组与C2组间存在显著差异(P≤0.05)。2)饲喂方式对德州驴盲肠微生物组成有一定影响。在门水平上,各组盲肠微生物均以厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)为主(二者占比>75%),其次为螺旋体菌门(Spirochaetes)、变形菌门(Proteobacteria)和纤维杆菌门(Fibrobacteres),且C2组厚壁菌门相对丰度高于C1组和C3组;在属水平上,将401个属中相对丰度低于1%的属聚为其他(占比>75%)后,各组均以其他为优势菌属;随后,C1组以螺旋体科未定义属(unidenti⁃fied⁃Spirochaetaceae)和厌氧孤菌属(Anaerovirbrio)为主,C2组以厌氧孤菌属、链球菌属(Strepto⁃coccus)和螺旋体科未定义属为主,C3组则以乳酸杆菌属(Lactobacillus)和螺旋体科未定义属为主。3)通过UPGMAA聚类树、主成分分析和物种差异性分析发现,3组德州驴盲肠微生物组成不同,且C2组与其他2组差别较大,C1组和C3组可聚为一类。综上可知,饲喂方式可极显著影响德州驴的平均日增重,显著影响干物质和酸性洗涤纤维消化率,并可改变盲肠微生物组成。     

小檗碱对炎症性肠病肠道屏障的影响及其信号通路

小檗碱是传统中药黄连等植物的主要活性成分,具有抗菌消炎、调节机体免疫等作用,可改善由炎症性肠病(IBD)导致的肠道屏障损伤。小檗碱通过抑制Toll样受体(TLRs)/核转录因子κB(NF⁃κB)、Janus活化激酶(JAK)/信号转导与转录激活子(STAT)信号通路和激活胰岛素样生长因子1(IGF⁃1)/胰岛素样生长因子结合蛋白(IGFBPs)信号通路,缓解IBD引起的肠道机械屏障、化学屏障、免疫屏障和微生物屏障功能损伤。本文就小檗碱的来源及理化性质、IBD的病理特征、小檗碱对IBD肠道屏障的修复作用及其信号通路进行综述,以期为畜牧生产中保护动物肠道健康提供参考。     

日粮精粗比对湖羊瘤胃发酵和菌群结构的影响

为了研究日粮精粗比对湖羊瘤胃发酵和菌群结构的影响,试验选择40只体重相近、体况良好且健康的湖羊羔羊,随机分为4组,每组10只(公母各半),各试验组羊分别饲喂精粗比70:30(A)、60:40(B)、50:50(C)和40:60(D)的全混合日粮,试验期为70 d。结果表明:1)试验B组的氨态氮、丙酸、丁酸和戊酸含量均显著高于试验D组(P<0.05)。2)4组共产生875个OTU,其中共有OTU为725个,占总OTU数量的82.86%,试验A和D组分别含特有OTU为6和1个。试验A组的细菌门数量和香浓指数显著高于试验C和D组(P<0.05),而辛普森指数则显著低于试验B和C组(P<0.05)。试验C组细菌多样性与试验A和B组差异显著(P<0.05)。3)在门水平上,试验A组的放线菌门(Actinobacteria)和螺旋菌门(Spirochaetae)相对丰度显著高于试验C和D组(P<0.05)。在属水平上,试验A组毛螺菌科_ND3007(Lachnospiraceae_ND3007)、密螺旋体属_2(Treponema_2)、魏斯氏菌属(Weissella)、厌氧支原体属(Anaeroplasma)、短杆菌属(Brevibacterium)、假丁酸弧菌属(Pseudobutyrivibrio)、未培养瘤胃杆菌属(Uncultured_rumen_ bacterium)和罗斯氏菌属(Roseburia)的相对丰度显著高于试验D组(P<0.05),而毛螺菌科_XPB1014(Lachnospiraceae_XPB1014)和未培养拟杆菌目_BS11(Uncultured _Bacteroidales_BS11)的相对丰度则分别显著低于试验C和D组(P<0.05)。综上所述,高精粗比日粮能够提高湖羊瘤胃细菌丰富度和多样性,促进瘤胃的发酵。     

淀粉发酵生产微生物多糖的研究现状

综述了国内外以淀粉为原料发酵生产微生物多糖的发展现状 ,着重介绍了近年来国内外关注的热点 :海藻糖、透明质酸等的研究现状 ,并列举了一些实现工业化或接近实现工业化生产微生物多糖的情况     

Growth performance,nutrient digestibility,and fecal microbial composition of weaned pigs fed multi-enzyme supplemented diets

A study determined the effects of supplementing corn-based diets for weaned pigs with multi-enzymes on growth performance, apparent total tract digestibility (ATTD) of nutrients, fecal score, and fecal microbial composition. A total of 132 pigs (initial body weight = 7.23 kg) that had been weaned at 21 d of age and fed a drug-free nursery diet for 7 d were housed in 33 pens of 4 barrows or gilts, blocked by body weight and gender, and fed 3 experimental diets at 11 pens per diet. The diets were corn-based diet without or with multi-enzyme A or B. Multi-enzyme A supplied 4,000 U of xylanase, 150 U of β-glucanase, 3,500 U of protease, and 1,500 U of amylase per kilogram of diet. Multi-enzyme B was the same as multi-enzyme A except that it supplied amylase at 150 U/kg, and that its source of amylase was different from that of multi-enzyme A. All diets contained phytase at 1,000 U/kg. The diets were fed for 35 d in 2 phases; phase 1 for the first 14 d and phase 2 for the last 21 d of the trial. Fecal score was determined daily during the first 7 d of the trial. Fecal samples were collected from rectum of 1 pig per pen on days 2, 7, 14, and 35 of the trial for determining bacterial composition. Also, fresh fecal samples were collected from each pen on days 41 and 42 to determine ATTD of nutrients. Multi-enzyme B increased (P < 0.05) average daily gain (ADG) for phases 1 and 2. For the overall study period, multi-enzyme B increased (P < 0.05) ADG from 262 to 313 g, and average daily feed intake (ADFI) from 419 to 504 g. Multi-enzyme A increased (P < 0.05) overall ADG from 262 to 290 g, but did not affect ADFI. Multi-enzyme A or B did not affect ATTD of gross energy, but increased (P < 0.05) the ATTD of ether extract from 30% to 36% or 37%, respectively. Multi-enzyme A did not affect fecal score; however, multi-enzyme B tended to decrease (P = 0.09) fecal score, implying that it tended to decrease diarrhea. Firmicutes were the most abundant phylum of fecal bacteria (its relative abundance ranged from 58% to 72%). Bacteroidetes and Actinobacteria were the 2nd and 3rd most abundant phyla of fecal bacteria. Neither multi-enzyme affected fecal bacterial composition. In conclusion, the addition of multi-enzyme A or B to phytase-supplemented corn-based diet for weaned pigs can improve their growth performance and fat digestibility. However, multi-enzyme B was more effective than multi-enzyme A in terms of improving the growth performance of weaned pigs fed corn-based diet.     

锌污染对猪粪堆腐过程中微生物群落的影响

利用Biolog微平板技术,对不同浓度重金属Zn影响下堆料微生物群落多样性进行了研究.结果表明,较低浓度Zn处理(Zn含量为400 mg·kg-1)的堆料升温快,高温持续时间长.微生物群落多样性指数和微生物群落主成分分析(PCA)指标均表明不同浓度重金属处理的堆料微生物群落有明显不同,Zn含量为400 mg· kg-1...     

废水同步生物处理与生物燃料电池发电研究

利用厌氧活性污泥作为接种体成功地启动了空气阴极生物燃料电池(ACMFC),110h的接种产生了0.24V的电压;以乙酸钠和葡萄糖作底物分别产生了0.38V和0.41V电压(外电阻1 000Ω),最大功率密度分别达到146.56 mW/m²和192.04mW/m²,表明有机废水可以用来发电;同时,乙酸钠和葡萄糖的去除率分别为99%和87%,表明燃料电池可以处理废水.二者的电子回收率均在10%左右,主要是由于阴极对氧气分子的透过作用引起的微生物好氧呼吸导致电子损失.     

Bioactive Compounds from Marine Sponges: Fundamentals and Applications

Marine sponges are sessile invertebrates that can be found in temperate, polar and tropical regions. They are known to be major contributors of bioactive compounds, which are discovered in and extracted from the marine environment. The compounds extracted from these sponges are known to exhibit various bioactivities, such as antimicrobial, antitumor and general cytotoxicity. For example, various compounds isolated from Theonella swinhoei have showcased various bioactivities, such as those that are antibacterial, antiviral and antifungal. In this review, we discuss bioactive compounds that have been identified from marine sponges that showcase the ability to act as antibacterial, antiviral, anti-malarial and antifungal agents against human pathogens and fish pathogens in the aquaculture industry. Moreover, the application of such compounds as antimicrobial agents in other veterinary commodities, such as poultry, cattle farming and domesticated cats, is discussed, along with a brief discussion regarding the mode of action of these compounds on the targeted sites in various pathogens. The bioactivity of the compounds discussed in this review is focused mainly on compounds that have been identified between 2000 and 2020 and includes the novel compounds discovered from 2018 to 2021.